I've made blog posts related to DIY LED grow light. I've been growing orchids for a while. I have less experience with carnivorous plants, but I do grow 100 or so CP species. I think the post is also useful for CP growing, so here are the links. I'm not familiar with the European market (cost of components and electricity), but you could save lots of money with high efficiency DIY LEDs. Hopefully, it could be useful for some people here.
Basics of LED drivers
DIY COB LEDs